Messages in this thread | | | Date | Wed, 15 Jul 2009 21:33:48 -0700 | From | Andrew Morton <> | Subject | Re: [PATCH 2/3] cciss: use only one scan thread |
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On Thu, 16 Jul 2009 04:15:59 +0000 Andrew Patterson <andrew.patterson@hp.com> wrote:
> > > +} > > > > We already did init_completion(h->scan_wait) at startup time? Doing > > the INIT_COMPLETION() here looks unusual and is hopefully unnecessary. > > > > I am following the text in the "Linux Device Drivers 3rd Edition section > 5.4: > > "A completion is normally a one-shot device; it is used once then > discarded. It is possible, however, to reuse completion structures if > proper care is taken. If complete_all is not used, a completion > structure can be reused without any problems as long as there is no > ambiguity about what event is being signalled. If you use complete_all, > however, you must reinitialize the completion structure before reusing > it. The macro: > > INIT_COMPLETION(struct completion c); > > can be used to quickly perform this reinitialization." > > It there are better way to do this? INIT_COMPLETION() currently just > sets done = 0.
OK, I'd assumed that a full wait_for_completion()/complete() operation would leave the completion in ready-to-use-again state.
But wait_for_completion_interruptible() can indeed leave completion.done in a non-zero state if it was interrupted by a signal. hm. Perhaps so the caller can run wait_for_completion*() again.
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